Channel insert attachment for a zipper foot

ABSTRACT

An attachment for a channel zipper foot accommodating the guiding of a zipper chain as the zipper foot stitches the zipper tape to garments. The attachment inserts into the channel of a zipper foot becoming engageable with the zipper tape. The configuration of the body of the attachment will retain the attachment into its inserted position during a forward or rearward stitch of the sewing machine operation. Zipper chains may be received into a channel formed into the underside of the attachment. A specially shaped attachment becomes an accessory part of a zipper foot to be inserted into a channel already present in the zipper foot, to provide the presser foot with a particular and specially shaped configuration of a channel which is capable of turning and rolling a concealed zipper chain from its otherwise natural position as it also guides the chain.

United States Patent 1191 'Gooderum 1451 Apr. 3, 1973 i541 CHANNELlNSERT ATTACHMENT FOR A ZIPPER FOOT [76] Inventor: Leoda J. Gooderum,627 Charles Street, La Crosse, Wis. 54601 22] Filed: Mar.3, l97 1 21Appl. No.: 120,534

[52] US. Cl. "112/240 [51] Int. Cl. ..D05b 29/12 [58] Field Of Search..1 12/235, 240

[56] References Cited UNITED STATES PATENTS 3,473,498 10/1969 Howell ..112/240 11/1957 Marshall 3/ 1969 Pingitore et al.

Primary Examiner Patrick D. Lawson Attorney-Robert E. Louie 57] ABSTRACTAn attachment for a channel zipper foot accommodating the guiding of azipper chain as the zipper foot stitches the zipper tape to garments.The attachment inserts into the channel of a zipper foot becomingengageable with the zipper tape. The configuration of the body of theattachment will retain the attachment into its inserted position duringa forward or rearward stitch of the sewing machine operation. Zipperchains may be received into a channel formed into the underside of theattachment. A specially shaped attachment becomes an accessory part of azipper foot to be inserted into a channel already present in the zipperfoot, to provide the presser foot with a particular and specially shapedconfiguration of a channel which is capable of tuming and rolling aconcealed zipper chain from its otherwise natural position as it alsoguides the chain.

5 Claims, 19 Drawing Figures PATENTEUAPR3 ms 3.724.408

SHEET 3 OF 3 CHANNEL INSERT ATTACHMENT FOR A ZIPPER FOOT This inventionrelates to an attachment for a zipper foot and more particularly to aguiding attachment for guiding and turning a zipper chain as the zipperfoot and the attachment engages and accepts the fabric adjacent to azipper as it is being sewn into a garment.

The insert attachment is described in connection with a zipper footattachment for a sewing machine. One such zipper foot is shown anddescribed in my copending application under Ser. No. 40,900, filed May27, 1970 which is an application as a continuation-in-part of my earlierapplication Ser. No. 736,166, filed June 1 l, 1968 and both applicationsare entitled Zipper Foot Attachment for Sewing Machines. The insertattachment will provide the zipper foot as identified in my applicationSer. No. 40,900, as well as others, capable of sewing a concealed zipperinto a garment.

A close stitch near the zipper chain is desirable to achieve a tightseam joining of the zipper tape to the fabric edges so that after theinstallation, the zipper tape will hardly be visible on the outside ofthe garment. To achieve this close stitch, a turning of the zipper chainaway from the sewing machine needle is needed so that during stitchingthe needle will not strike the zipper chain and damage its teeth. Theone piece attachment of the present invention is of a specific shapeallowing it to be inserted into a channel and into the needle slot of azipper foot. The insert has a channel shaped into its underside which isof a specific configuration formed so as to turn over the zipper chain.

Separate attachments provided with a channel and designed to be insertedinto a channel of a zipper foot are known. Howell, US. Pat. No.3,473,498 discloses two separate and different types of insertattachments to accompany a channel zipper foot. Both inserts will guideand turn a zipper chain of a concealed zipper, providing the channelzipper foot with the means for proper installation. One of the twoattachments disclosed is designed to be inserted around therearcurvature of the needle hole in a hook fashion. This style of insertwill require a seamstress to perform a delicate 'handling of the piecewith difficult maneuvering to hook and'snap the piece into its insertedand useable position. Also, disclosed is the other type of insert inmodified form. This piece is inserted into a front recess in the channelof the zipper foot. However, this front piece will become disengagedfrom the recess when a back stitch is supplied. The sewing process ofback stitching is a required step during the installation of a concealedzipper and is applied after one side of the zipper tape is joined to thefabric. Next, it will again become necessary to insert the front piece asecond time, presenting an inconvenience, to complete the joining of theother side of the zipper tape. Furthermore, as the front piece detaches,the zipper chain is solely guided and turned by the rear hook insert andtherefore guided only rearward the needle. The foregoing zipper insertattachments are thus limited in use and involve certain inconveniences.An important object of the present invention is to provide a one pieceinsert attachment which will produce a turning and guiding treatment toa zipper chain both frontward and rearward the needle. A further objectis to provide an insert attachment which will remain inserted intoposition and which will not become disengaged from the zipper foot as aback stitch or forward stitch is applied during the sewing operation.Another object is to provide an insert attachment which is inexpensiveto manufacture, easy to insert and easy to remove by the seamstress,simple to use; and which will convert the channel already present in azipper foot to provide a new channel capable of turning, as well asguiding, a zipper chain. It is also an object to provide interchangeableinsert attachments, of which there could be several, allowing aselection of various inserts, and each provided with different lateralconfigurations to guide zipper chains of different thickness or to guideother objects having elongated raised bodies, such as cordings.

The insert attachment of the present invention features a one piece unitwith bodies forming a configuration of a substantially T-shaped block.One rectangular length of the T-block has a channel underside which willbecome inserted into the channel already present in a zipper foot,having its channel underside to the bottom side of the zipper foot,bothforward and rearward the needle. The insert attachment becomes theguiding channel and its channel is of a shape and configurationdifferent from the channel of the zipper foot into which it is inserted.The other portion of the T-block is a protruding body, a finger shapedplug, which will insert into the needle slot of the zipper foot in aplug fashion. The finger plug also serves to contain the attachment inposition during a forward or backward stitch. Also,

when one rectangular body is positioned between the channel and theother finger portion plugged into the needle slot, the T-block isfrictionally held and removably attached to the zipper foot. The channelof the attachment has two side legs with a triangular V- shaped bodybetween and a needle slot formed substantially through the center of theV-body. This will provide the channel attachment with two tunnelsections on either side of the V-shape. One tunnel will receive and turnguide the open zipper chain on one side of the zipper tape, while theother tunnel will receive and guide the opposite zipper chain. Thisspecially shaped V portion is therefore the means which will produce theturning or rolling over of the zipper chain as it is fed and guided intothe tunnel during the stitching producing the proper installation of theconcealed zipper.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part thereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the insert attachment constructed inaccordance with the present invention.

FIG. 2 is a perspective view of a zipper foot showing the insert placedin position for use.

FIG. 3 is a rear view of the zipper foot showing a sub:

stantially wide-spread adjustment of one limb element from the other.

FIG. 4 is a top plan view of the attachment and the zipper foot showingthe attachment inserted between the extended limb elements and'alsoshowing a phantom portion of the slide body for the purpose ofidentifying the position of two threaded bores, also illustrated inphantom.

FIG. 5 is a top plan view of the auxiliary element removed from itsnormal attached position onto the zipper foot of FIG. 2.

FIG. 6 is an enlarged partial section view taken substantially through aplane indicated by section line 6-6 in FIG. 4.

FIG. 7 is an enlarged partial sectional view taken substantially througha plane indicated by section line 7--7 in FIG. 41 including one side ofan open zipper chain as seen in FIG. 10, illustrating the leaningtreatment applied to the zipper chain by the insert attachment and alsoshowing the feeding elements of a sewing machine.

FIG. 8 is a perspective view of the insert attachment showing itsunderside to view its channel configuration.

FIG. 9 is an enlarged sectional view taken substantially through a planeindicated by section line 9-9 in FIG. 4 showing the plug element of theinsert attachment positioned into the needle slot of the auxiliary limbelement of the zipper foot.

FIG. 10 is an enlarged sectional view taken across one side of an openchain and zipper tape showing the teeth elements of a concealed zipperchain positioned in their natural attitude.

FIG. 11 is a perspective view of a modified form of the insertattachment constructed in accordance with the present invention.

FIG. 12 is a perspective view of a common type zipper foot showing themodified insert placed in position for use.

FIG. 13 is anenlarged partial sectional view taken substantially througha plane indicated by section line 13--l3 in FIG. 12 showing in sectionalthe face of the triangular V-body and the extending nose plug and alsooneside of an open zipper chain as seen in FIG. 10, illustrating theleaning treatment applied to the zipper chain by the modified attachmentand also showing the. feeding elements of a sewing machine.

FIG. 14 is an enlarged partial sectional view taken substantiallythrough a plane indicated by section line 14l4l in FIG. 12 showing theplug element of the modified insert attachment positioned into theneedle slot of the common type zipper foot.

FIG. 15 is a perspective view of still another modified form of insertattachment constructed in accordance with the present invention.

FIG. 16 is a perspective view of the common type zipper foot, identicalto FIG. 12, showing the modified insert of FIG. 15 positioned for use.

FIG. 17- is an enlarged partial sectional view taken substantiallythrough a plane indicated by section line 17-17 in FIG. 16 showing insectional the face of the triangular V-body and one side of an openzipper chain as seen in FIG. 30, illustrating the leaning treatmentapplied to the zipper chain by the modified attachment and also showingthe feeding elements of a sewing machine.

FIG. 18 is an'enlarged partial sectional view taken substantiallythrough a plane indicated by section line 18-18 in FIG. 16 showing thelip gripping elements of the modified insert attachment gripping thefront and rear of the common type zipper foot.

FIG W is a perspective view of a modified form of the finger plug of theattachment of FIG. 1 showing the attachment positioned for use in anauxiliary element form of zipper foot.

Referring to the drawings in detail and initially to FIG. I, it will beobserved that the T-block attachment is generally denoted by referencenumeral 10. The T- block includes an elongated rectangular base 12,shaping at its front to a tapered nose 13, with a channel 14 formed intoits underside. A needle hole 16 is bored through the center of the baseand a finger shaped plug 18 extends substantially perpendicular to thelengthof the base and from one side adjacent to the region where theneedle hole is formed.

The T-block is an attachment or accessory part to ac.- company a channelzipper foot. The outside contour of the T-block is shaped in aconfiguration of a T 50 as to removably insert the T shape block into anelongated channel and into a needle slot of a zipper foot as seen inFIG. 2. A zipper chain 19 may then pass and be guided through thechannel formed into the T-block.

Features required within a channel zipper foot to provide the T-blockinsertable and useable include; a channel with an overhead sectionproviding the channel with a roof, and a needle slot. A zipper foot ofthis type, including these features, is shown in FIG. 2 and is generallydenoted by numeral 20. The following description is offered to outlinethis zipper foot, pointing out the requirements as stated above andshowing how these features are used in combination with the T block toafford the insert useable.

Referring to FIG. 2, the zipper foot assembly 20 includes a supportmember 22 with an extended elongated grooved guide portion 24 andclamping means 26 to removably mount the zipper foot onto the presserbar 28 of the sewing machine by clamping screw 30.

A slide body 32 includes a material engaging main limb 34 extendingtoward a needle 36 of the sewing machine. The slide body 32 is mountedonto the grooved guide portion 24 and is slidably received between itsupper leg 25 and lower leg 27 by means of a rear threaded clampingscrew38. As seen in FIG. 3, the rear clamping screw 38 extends through ahorizontal adjustment slot 40 formed into the elongated grooved guideportion 24. The rear clamping screw next enters into a threaded borehole 42, shown in phantom in FIG. 4, formed into the rear of the slidebody 32. Thus, the slide body and its extended main limb is movablymounted to the support member. This mounting means provides the mainfoot element capable of being frictionally locked in a plurality ofadjusted positions on the support member and to positions on either sideof the needle.

A second auxiliary material engaging limb 44 is slidably mounted ontothe slide body 32 of the main limb element in a manner similar to thatof the slide body mounting onto the support member. Referring to FIG. 2,it is observed that an elongated groove face 46 includes an upper leg 48and a lower leg 50 adapted to receive the slide body 332 between saidlegs, as more clearly seen in FIG. 9. The auxiliary limb element 44 isthus slidably received onto the slide body and may be locked in aplurality of adjusted positions by means of a front threaded clampingscrew 52. The front clamping screw enters through a horizontaladjustment slot 54 formed through the elongated grooved face and thescrew proceeds to enter into a threaded bore hole 56, shown in phantomin FIG. 4, formed into the front of the slide body and longitudinallyspaced from the rear threaded bore 42. Thus, the auxiliary limb ismovably mounted onto the slide body with adjustment offering selectiveand frictionally locked space relation toward and from the main limb.This provides the zipper foot with a selective and changeable widthchannel 58 formed between the two extended limbs 34 and 44, as moreclearly seen in FIG. 3 (a wide channel selection is shown, for purposesto be described hereafter). The fixed width of the channel will beselected as such to accept the base 12 of the T-block between the limbs(see FIG. 4) which will be described hereafter in greater detail.

Referring again to the zipper foot assembly in FIG. 2, a mounting arm 60is of an inverted L shaped configeration so as to form a passage 62,which will allow the slide body 32 and the attached groove face 46 to bedisplaced through the passage 62. Therefore, the main limb 34 and theattached auxiliary limb 44 are slidably displaceable to at least allowpositioning of their inside edges 77 and 79 (see FIG. 3) to oppositesides of the sewing machine needle when the T-block is inserted.

For and a more detailed description of the main limb element, theauxiliary limb element and the support member of the zipper footassembly, reference is made to my aforementioned copending applications,Ser. Nos. 736,166 and 40,900.

Referring to FIG. 5, the auxiliary limb element is divided into twofabric engaging sections, front section 66 and rear section 68. A U-arm70 connects said sections and a needle slot 72 develops inside the openarea formed between the two sections. The U-arm is also designed toreceive the needle of the sewing machine into its open area 74 formedinside the U-arm. The needle slot 72 is in alignment with the extendingU-arm, thus, the open area 74 actually becomes an extension in length ofthe needle slot 72. Therefore, the needle of the sewing machine may bereceived into the length of the needle slot and continue into andthrough the open area of the U-arm, as the two limbs are laterallyadjusted, with selective and fixed positioning of the limbs relative tothe needle. The U-arm also features an elevated bend 76 (see FIG. 2)allowing the U-arm to freely move above the main limb 34 when a selectedand fixed position of the auxiliary limbs inside edge 77 (see FIG. 3) isplaced from the main limbs inside edge 79, in order to form the channel58 between.

For a more detailed description of the U-arm assembly of the auxiliarylimb element, reference is made to-my aforementioned copendingapplication Ser. No. 40,900.

As hereinbefore indicated, one of the necessary features within achannel zipper foot required to provide the If-block insertable,includes a section of roof above the channel. It is observed in FIG. 5,that the U-arm provides this roof as the U-arm includes a frontextension 78 and a rear extension 80. The rear extension is shown abovethe channel in FIG. 3, while the front extension is shown above thechannel with the T-block inserted in FIG. 6. Therefore, both the frontand rear extensions of the U-arm serve to provide a partial roof abovethe channel in a region forward and rearward the needle hole 16 (seeFIG. 4).

Now, reference is made to the T-block and to the manner in which it willbe inserted into the channel and under the U-arm of the zipper foot. Itis observed in FIG. 6, that the height of T-bloclr is determined by thedistance between its fiat plain topside 82 to its underside 84. It isalso observed that the front extension 78 of the U-arm includes anunderside 86. Likewise, the rear extension also has an underside 88, asseen in FIG. '7. The height dimension of the T-block is only slightlyless than the distance measured between the undersides of both U-armextensions to the underside of the auxiliary limb (see FIG. 6).Therefore, the height of the T-block is predetermined and is such toallow its elongated base to rest under and in abutment with theunderside of both the extensions of the U-arm (FIGS. 6 and 7), while theT-blocks underside 84, the auxiliary limbs underside 90 and theunderside of the main limb have their lowermost undersides thereof atthe same level, as seen in FIG. 6.

The breadth of the base 12 of the T-block is defined as the dimensionbetween its two outside edges 92 and 94 (see FIG. 8). The breadth willbe such to allow the channel 14 to be formed into its elongatedunderside. As hereinbefore indicated, the zipper foot 20 features anadjustable width channel, therefore the edges 77 and 79 of the twoextended limbs, will be selectively adjusted and fixedly spaced at awidth only slightly wider than the breadth of the base 12, thus allowinga snug abutment and frictional insert of the base edges into thechannel, as seen in FIG. 6.

Referring to FIG. 8, the channel 14 of the T-block is shaped bothforward and rearward the needle hole 16. The channel is of aconfiguration so as to produce a turning treatment to a zipper chain asseen in FIG. 7, by its camming action which will be explained in greaterdetail hereafter. In describing the channel configuration, reference ismade to FIGS. 6 and 8 where it is observed that a substantiallytriangular V-body 116 is formed by the base topside 82 and two obliquewalls 122 and 124 slanting at an incline and diminishing to a centervertex 126. Two legs 122 and 124 are extended in a perpendiculardirection from the topside base 82 and extended in equal distancedownward and toward the vertex 126, including two inside walls 112 and114, respectively. The vertex does not extend below the underside of thelegs.

Reference is now made to the finger plug 18 which extends from the samelevel of the base topside 82 and leg bottomside 84. The breadth of thefinger plug is predetermined and such to allow it to insert snugly intothe needle slot of the auxiliary limb. The breadth is defined as thedimension between its front side 96 and its rear side 98 (see FIG. 8).This breadth dimension is only slightly less than the needle slotopening indicated from the needle slots front wall 100 to its rear wall102, as clearly seen in FIG. 5. Now, referring to FIG. 9, the insertingof the finger plug is observed as its outside edges 96 and 98 abut thetwo walls 100 and 102 of the needle slot. This type of insert could bedescribed in a manner or fashion as a plug and socket insert. The needleslot serves as the socket in which to plug the finger extension Thusinserted, there becomes a certain amount of frictional gripping of theabutting surface edges of the base legs and the finger plug, which willdiscourage the T-block from falling out from its inserted placement.

One convenient manner in which to insert the T- block would be to firstspread the two limbs, allowing a wide channel separation (see FIG. 3);next, insert the finger plug into the needle slot of the auxiliary limb;and finally, adjust the auxiliary limb laterally toward the main limbuntil the outside edge of the T-blocks leg touches and abuts the insideedge of the main limb.

' Still, another method of easy inserting would be to first laterallyadjust the auxiliary limb a selected distance from the main limb so thatthe channel width is just slightly wider than the breadth of the base;then from the underside of the limbs, position the. shape of the T-block to coincide with the channel opening and the needle slot openingand push the T-block from its channel underside and it will insert intoposition for use. The zipper foot will be attached to the sewingmachine, adjusting the limbs to align the needle above the needle holeand the insert attachment is-rcady to receive a zipper chain.

Referring to FIG. 7, the zipper tape 134 and fabric 106 are fed by meansof the sewing machine feeding elements 108, while the fabric and zipperare pressed down onto the bed 109 by the zipper foot and the T- block.When applying a front stitch, the action of the feeding elements is oneupward and rearward motion, in contact with the fabric and pushing thefabric and zipper rearward of the needle. Next, the feeding elementsdrop downward and out of engagement with the fabric and move forward forits next upward and rearward circular cycle. The motion of this cycle isrepeated in cooperation with the reciprocating needle and other actionswithin the sewing machine, producing the actual stitch joining of thefabric and zipper tape. During the front stitch feeding, the rearwardmotion of the feeding elements will also be exerted to the undersidelegs of the T-block and will likewise react upon it with a rearwardpushing. A rearward movement of the T block is discouraged, however,because as earlier indicated, the rear edge 98 of the finger plug is inabutment with the rear wall 100 of the auxiliary limbs needle slot (seeFIG. 9). Next, a back or reverse stitch may be applied from the feedingelements to the fabric and zipper, which is a reverse action or motionin comparison to the frontward stitch. In this case, the feedingelements move upward and frontward during their cycle causing the fabricto move in thissame direction. Again, the T-block willhave a tendency tomove in a likewise frontward direction, because this frontward motion isexerted to'the underside of the T- block. However, a frontward movementis discouraged because as previously indicated, the front edge-96 of thefinger plug abuts the front wall 100 of the needle slot of the auxiliarylimb. Thus, the finger plug serves to restrain forward and-rearwardmovement and serves to contain the T-block into its position between thechannel of the zipper foot.

As hereinbefore indicated, the auxiliary limb is attached to the mainlimb. Also, the base topside of the T-block abuts both undersidesections of the U-arm. This abutment will serve to contain the T-blockinto its position between the two limbs while the lowermost undersidesof the main limb, the T-block, and the underside of the auxiliary limbremain at the same level. Also, because of this abutment and theattachment of the two limbs, the equal level of the three undersides 95,8d, and (see FIG. 6), is maintained even though an uneven thickness offabric 106 and zipper tape 134 are under only one of the two limbs, asmore clearly seen in FIG. 7. Then too, the upward and vertical movementfrom the feeding elements is transmitted through the T-block and throughboth limbs, again by reason of their abutment and attachment. Theultimate upward motion is carried to the presser bar of the sewingmachine and provides displacement of the presser bar in both directionsbecause the zipper foot is attached thereto. Thus, both limbs 34 and 44and the T- block 10 are displaceable by the feeding elements incoordination during engagement with the zipperand fabric being fed alongthe machine bed 1 10. For a more detailed description of thedisplacement action of the presser bar through the zipper foot itself,reference is made to my two copending applications, Scr. No. 736,166 andSer. No. 40,900.

The arrangement of the triangular V-body and the side legs will providethe channel 14 with two tunnels, 128 and 130.and each tunnel isthree-sided and of substantially equal configuration. The contourforming tunnel 128 includes outside wall 112 and oblique wall 122.Likewise, the contour comprising tunnel includes outside wall 1 14 andoblique wall 124. Referring to FIG. 7 and 8, the needle hole 16 isformed through the topside 82 of the base and substantially through'thecenter vertex 126 of-the triangular V-body to receive the needle 36.

FIG. 10 shows the natural attitude of the zipper teeth 19 of a concealedzipper, being in a substantially upright position. Referring to FIG. 7,the open chain 19 of zipper tape 134 is initially fed during, the sewingoperation, into tunnel 123 and the slantingside wall 122 of thetriangular V-body will produce the carnrning action to the zipper chainand will turn and roll the chain away from its otherwise naturalattitude, both forward and rearward the needle. The zipper chain is alsoreceived in sliding abutment with the wall 1-12 and is thereforecontainedand guided past the reciprocating needle. Therefore, the needlewill stitch near the zipper chain but will not strike the chain anddamage it because the chain is turned and rolled away from the needle.The opposite tunnel 130 will be used when joining zipper tape 132 to thefabric, as seen in FIG. 2. Here, the tunnel 130 will produce a likewiseturning treatment to the zipper chainas a result of the slanting side124 (FIG. 6) producing the camming action; and in combination with wall114, will produce the longitudinal guiding.

It is possible to provide more than one T-block for interchangeableinserts. Each T-block would have different channel configurations toaccept a variety of different size zipper chains or shapes of raisedlongitudinal bodies. If wider channels are formed into the insert, thebase of the T-block will accordingly become broader and a wider channeladjustment will be selected to accommodate the inserting of a widerbase.

Thus, the zipper foot 20 is readily adjustable for inserting varioussize T-blocks.

In FIG. 19, a modified arrangementof the finger plug 18 will provide theT-block attachment useable on another type of zipper foot 23. Thiszipper foot is composed of an auxiliary limb element and is of the typedisclosed in FIG. 7 of my copending application Ser. No. 40,900. It isobserved that the main limb, which served to contain the leg edge 92' ofthe T-block is not a feature of this zipper foot. Therefore, and becausethe main limb is eliminated, the modified finger plug 18' includes acrossbar 29 having two inside sections 31 and 32 which will serve tofrictionally grip and abut one outside edge 45, while the leg edge 94'of the T-block abuts the other edge 77' of the auxiliary limb 44'. Thisabutment is achieved because the dimension from the leg edge 94' to theinside sections 31 and 32 of the crossbar is predetermined and onlyslightly greater than; the dimension of the breadth of the auxiliarylimb measured between its edges 77' and 45. This abutment will containthe leg edge 94 of the T-block against the inside edge 77 of theauxiliary limb and will discourage a sideway movement of the base 12' asit rests under the U-arm 70'. The base 12' with its channel 14' hasidentical features and functions of guiding and turning a zipper chainas hereinbefore indicated.

FIG. 11 shows a modified arrangement of the insert attachment and willhereafter be referred to as T-block This form of insert will beparticularly desirable when used in combination with a common or basicmodel channel zipper foot, shown in FIG. 12, and hereafter referred toas numeral 21. This zipper foot features an elongated extended limb 35with a channel 37 formed into its elongated underside, a roof section 39and a needle slot 41 (as clearly seen in FIG. 16). Here, the channel 37is of fixed width, having two channel walls 113 and 115 (FIG. 13).Therefore, it is only required to supply a triangular V-shaped body 116'insertable into the channel to provide the channel with a cammingability.

The modified T-block 10' differs from the T-block 10 (seen in FIG. 8)with the elimination of the two side legs 118 and 120 and also differswith the placement of a newly shaped nose plug 17, as seen in FIG. 11.The nose plug replaces the finger plug.

Referring to FIG. 11, 13, and 14, the T-block features the substantiallyisoceles triangular V-body 116' including its base top 82 and twooblique side walls 122' and 124 slanting to a center vertex 126. Thebreadth of the base is the distance between two points 136 and 138. Thebreadth is predetermined and such to allow a frictional insert of thetriangular V-body 116' into the channel, while its points 136 and 138touch the channel walls 113 and 115, respectively (FIG. 13). In FIG. 14,it is observed that the base topside 82' of the triangular V-body is inflush abutment with the roof 39 of the channel while its vertex 126'does not extend lower than the channel side walls 113 and 115.

It will be observed in FIG. 11 and 14 that the nose plug !7 protrudesfrom the base topside 82 of the triangular V-body. The nose plug will beinserted into the needle slot 41 (more clearly seen in FIG. 16) of thezipper foot and is of a circular configuration equal to the circularconfiguration of the needle slot opening. Also, the outside perimeter ofthe nose plug is only slightly less than the inside perimeter of theneedle slot to allow the snug and frictional insert in a plug and socketfashion. The nose plug is shown and described in a round shape, however,it could be of other shapes which would conform to the configuration ofother needle slot shapes.

As hereinbefore indicated, during the sewing process the feedingelements 108 (FIG. 13) exert either a forward or rearward pushing actionto the underside of the fabric 106 and zipper tape 134, and the zipperfoot 21.

This action is also exerted to the vertex 126' and the oblique wall 122'(FIG. 13) through the fabric and the zipper and will create a tendencyto move the T-block 10' in a likewise direction. However, in FIG. 14 itis observed that the front and rear curvatures 117 and 119 of the noseplug 17 are in abutment with the front and rear curvatures 121 and 123,respectively, of the needle slot. This abutment will discourage aforward or rearward movement of the T-block.

Referring to FIGS. 11 and 13, a needle slot 16' is formed substantiallythrough the center of the nose plug 17 and through the center vertex126' for needle reception.

In FIG. 13 it is observed that a tunnel 128' is formed by the obliquewall 122' and the channel wall 113 of the zipper foot. The tunnel willreceive the zipper chain 19 with the oblique wall 122'. exerting its camaction to lean the chain in an outward position, both forward andrearward the needle, as well as away from the needle. Also, the chain isguided longitudinally as it is also contained by the channel wall 1 13.Likewise, tunnel 130' is formed by oblique wall 124' and thewall 115 ofthe channel and the tunnel 130 will produce the same guiding and camaction to the zipper chain, as seen in FIG. 12.

Furthermore, as the zipper chain is fed into one of the two tunnels, thefeeding elements exert an upward force upon the fabric and zipper chain.This upward force is first transmitted through the fabric and zipper tothe underside 153 of the zipper foot and through the oblique wall 122'and vertex 126' of the triangular V- body. As earlier indicated, thebase topside 82' of the triangular V-body abuts the channel roof 39.Thus, the upward vertical force is carried through the T-block and thezipper foot, to the lower end of the presser bar 28 where the zipperfoot is attached; providing vertical displacement of the presser bar inboth directions.

FIG. 15 features still another modified form of the insert attachment,including means to adopt the zipper foot 21 with the triangular V-bodyextending from its channel roof, as seen in FIG. 16. It will be observedthat the insert attachment has appearance of an overall 1-configuration; so hereafter, the descriptive reference to the insertwill be entitled the I-block, numeral 15 The triangular V-body 116" isalso a feature of the I- block and will also perform identical to thetriangular V-body 116' of the T-block 10', because it is identical instructure, as seen in the comparison of the faces of includes anelongated tail 125 (see FIGS. 15 and 18) extending rearward from one endof the triangular V- body 116", including a rear lip 129 forming upwardand perpendicular from one end of the tail, having an inside face 133.Also, extending upward from the front face of the triangular V-body is aprojected from lip 127 also having an inside face 131. A description ofhow the two lips provide the frictional gripping will follow.

Referring to FIG. 18, the dimension measured from the front inside face131 to the rear inside face 133 of the I-block is only slightly morethan; the dimension measured from the front nose 140 to the rear end 142of the zipper foot. Therefore, when the triangular V- body 116" ispositioned and inserted between the channel walls, the inside faces 131and 133 will frictionally grip and abut the ends 140 and 142,respectively; while the needle slots 16" and 41 fall into alignment.The position of the l-block needle hole 16" is therefore a selected andpredetermined distance from its front lip 127. The abutment of the lipswith the zipper foot is the means by which the I-block will remaincontained in its inserted position during a frontward or rearward motionexerted from the feeding elements.

Both the T-block l and the l-block provide easy inserting. A simplealignment of the nose'plug with the needle slot will obtain the insertof the T-block as it is pushed from its underside. In the case of theI-block, simple positioning of its lips in alignment to receive thelength of the zipper foot limb between, pushing upward, will allow thelips to snap around the limb.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. In combination with a sewing machine presser foot attachmentincluding spaced-apart forward and rearward material engaging portions,said portions being operatively connected by a U-shaped member, theimprovement comprising an insert having a longitudinal portion and atransverse portion, said transverse portion adapted to fit snugly intothe space between said forward and rearward material engaging portions,said longitudinal portion having a triangular rib along the centralportion of its underside. I

2. The apparatus of claim 1 wherein said longitudinal portion includesside walls depending from the longitudinal edges of the undersidethereof, said side walls and said rib cooperating to form paralleltriangular channels on each side of the apex of said rib.

3. The apparatus of claim 1 wherein said longitudinal portion includes aneedle receiving aperture in the central portion thereof.

4. The apparatus of claim 1 including a third material engaging portionspaced transversly from and substantially parallel to said forward andrearward material engaging portions forming a longitudinal .slottherebetween and wherein said longitudinal portion of said insert isadapted to fit snuglyin said longitudinal slot.

5. The apparatus according to claim 4 wherein said forward and rearwardmaterial engaging portions are moveable in a transverse direction towardand away from said third material engaging portion, whereby the width ofsaid longitudinal slot may be varied to firmly grip said insert. v

l I II

1. In combination with a sewing machine presser foot attachment including spaced-apart forward and rearward material engaging portions, said portions being operatively connected by a U-shaped member, the improvement comprising an insert having a longitudinal portion and a transverse portion, said transverse portion adapted to fit snugly into the space between said forward and rearward material engaging portions, said longitudinal portion having a triangular rib along the central portion of its underside.
 2. The apparatus of claim 1 wherein said longitudinal portion includes side walls depending from the longitudinal edges of the underside thereof, said side walls and said rib cooperating to form parallel triangular channels on each side of the apex of said rib.
 3. The apparatus of claim 1 wherein said longitudinal portion includes a needle receiving aperture in the central portion thereof.
 4. The apparatus of claim 1 including a third material engaging portion spaced transversly from and substantially parallel to said forward and rearward material engaging portions forming a longitudinal slot therebetween and wherein said longitudinal portion of said insert is adapted to fit snugly in said longitudinal slot.
 5. The apparatus according to claim 4 wherein said forward and rearward material engaging portions are moveable in a transverse direction toward and away from said third material engaging portion, whereby the width of said longitudinal slot may be varied to firmly grip said insert. 